Liquid fuel-burning heater



April 6, 1965 E. s. DOWNS 3,176,749

LIQUID FUEL-BURNING HEATER Filed Feb. 25, 1965 3 Sheets-Sheet 1 [8 i I I2 \1 w INV NTOR EDGAR s pow/vs fi -g MAli/VEY, MILLERQRAMBO ATTORNEYSApril 1965 E. s. DOWNS 3,176,749

LIQUID FUEL-BURNING HEATER Filed Feb. 25, 1963 3 Sheets-Sheet 2INVENTOR. EDGAR 5'. DOW/V5 BY MAHONEY, MILLER 8 RAMBO ATTORNEYS A ril 6,1965 E. s. DOWNS 3,175,749

LIQUID FUEL-BURNING HEATER Filed Feb. 25, 1963 s Sheets-Sheet sINVENTOR. E 0634/? S DOW/VS ,M/LLER aanwaa FIGURE 5.

LiQUIi) FUEL-BURNING HEATER Edgar S. Downs, Worthington, Ohio, assignorto Burner This application is a continuation-in-part' of my'copendingapplication Serial No. 183,251, filed March 28, 1962-, now Patent No.3,127,924 dated April 7, 1964, and which, in turn, is a division ofapplication Serial No. 37,874, filed June 22, 1960, now Patent No.3,029,863, dated April 17, 1962. i

My invention relates to a liquid-fuel-burning heater. It has to do,moreparticularly, with the burner of a heater of the oil-burning type.It relates to that general type of oil-burning burner which uses amechanical spinner that receives theoil from a source of supply andthrows it outwardly by centrifugal force through a surroundingcombustion chamber so thatit is directed onto an: annular wall of highcapillarity which receives and absorbs, the' droplets thrown otf by thespinner and in which the droplets spread to provide a large area forrapid-evaporation and burning of the oil.

More specifically, this invention relates to that type of burnerdisclosed in my Patent No; 3,029,863, issued April 17, 1962. The burnerdisclosed in said patent has gone into wide commercial use as alightweight portable space heater, especially by building contractorsand the like who need a smokeless burner that will developa high heat ata relatively low cost. However, in adapting this burner to permanentlyinstalled commercial and residential heating equipment, it was founddesirable to make certain improvements therein whichwould make theburner function even more efliciently in' such equipment wherethe'burner operates at a higher temperature.

embodying the "present I invention.

' FIGURE 2 is an enlarged axial sectional view taken along line 22:ofFIGURE 1 through the burner, showing the non-absorbent bafiie ring andassociated annular absorbentwall. i

. FIGURE 3 is an enlarged, axial, sectional view taken along line 3-3 ofFIGURE 2 through the spinner.

FIGURE 4 is a transverse, sectionalview taken along FIGURES is atransverse, sectional view taken along line"5-5 of FIGURE 2.

FIGURE 6 is an enlarged, sectional, diagrammatic view taken at theposition indicated by line 6-6 of FIGURE'7 is a diagrammatic,transverse, sectional view illustrating a modification of the bafiiering.

FIGURE 8 is a diagrammatic, transverse, sectional view illustratinganother modification of the bafile ring.

FIGURE 9 is a diagrammatic, sectional view showing,

a baffler'ing of different cross section.

FIGURE 10 is a view similarto FIGURE 9 but show- 6 ing the ring made ofa plurality of wires or the like.

FIGURE 11 is another view similar'to FIGURE 9 but showing a baffle ringof another cross section.

. The burner of this invention in its general structure is stalledheating equipment whichoperatesjat higher tem- United State P atent Operatures. It is shown in the drawings as having its spinner axisupright but his to be understood that the burner will function equallyas well with the spinner axis t in FIGURE '2.

FIGURE 2.

in a horizontal position. v

The burner is shown in FIGURE 1 disposed withina tubular outer casing 15which may be suitably connected to a stack or vent when incorporated ina domestic furnace. A fan 16 is disposed within the casing 15 coaxialtherewith at the lower inlet portion thereof being mounted on a shaft 17which is preferably driven by an electric motor. x

Disposed within the t casing 15 in spaced concentric relationshiptherewith upwardly toward the outlet thereof is the combustion chamber18 which is mainly of tubular form. Since it is of smaller diameter thanthe casing 15 an annular air-passageway 19 is provided between the wallof the combustion chamber and the casing 19. The fan 16 is of suitableform to draw air upwardly into the casing 15 and force it upwardlytoward the outletof the casing through the annular space 19. and thecombustion chamber 18.

The burner is indicated generally at 20 and is concentrically disposedwithinthe combustion chamber 18 at .the lower or inlet end thereof. Justabove or beyond provided with a disc or back plate 22which substantiallyclose s it except that it is provided with an. air inlet opening 23.This opening 23 serves as the primary air metering opening throughwhich'the main supply of primary air is supplied to the burner 20 by thefan 16. The shaft 17 extends forwardly through the opening 23 and itwill .be noted that this shaft is hollow for conducting the fuel oil toa supply of which it maybe suitably connected.

The burner 20 includes the annular absorbent ring or burner wall 25fitted snugly within 'the combustion chamber wall at the lower or inletend thereof as shown best It may be suitably fastened in position as bymeans ofthe screws 26. As disclosed in my prior patent, the wall 25 ismade of a suitable liquid-absorbent, heat-resistant material of highcapillarity. It may be of various materials such as ceramic paper orfelt but I preferto use a ceramic woven cloth; For supplying part of theprimary air for] combustion, through the porous cloth wall, one or morerows of angularly spaced openings- 27 are provided extending throughthewall or the combustion chamber 18 at thewall25. However, it will benoted that these openings do not extend thro ugh. the

absorbent porous cloth wall 25. Between the primary spinner initsgeneral construction is likejthat disclosed in said patent but isimproved to make it function even axial with the absorbent burner wall25. The spinner is located directly forward or above the plate 22inassociation with the opening 23-therein as shown best in Although thisspinner is of the. general structure =disclosed in my patent, I havefound that in some instances, as in a residential furnace wheretemperatures are higher,

it isflnecessary to provide for a redncedtemperature at 3,i76,749Patented Apr.- 6,1965

It is carried by the shaft17 and is co the oil spinner or slinger so asto prevent evaporation of the oil before it leaves the surface of thespinner. If oil leaves the surface of the spinner in the vaporizedstate, it does not travel far from the spinner due to its low inertia ascompared to the liquid oil, thus causing an overly rich area in thevicinity of the spinner which causes excessive carbon formation on thespinner;

As one means of preventing overheating of the spinner, the front'orupper surface of the forwardmost or uppermost metal spinner disc 31 iscompletely covered with a thick disc or lamination 32 of thermalinsulating material.

This has been found to reduce very sharply the temperature at the rearor lower portion of the spinner due to the fact that metal at theforward side and which is attached to the rear side of the spinner isnot exposed directly in the flame produced by the burner.

Another means of reducing the temperature of the spinner is in providingopenings in the plate or disc 33 which is directly behind or beneath theplate 31 and in spaced relationship thereto. These openings 34 may be inspaced angular relationship around the center of the plate 33 concentricwith a bolt 35 which holds the plate 31 on the plate 33, a spacer washer36 spacing the two plates apart to providethe air space 37 therebetwecn.This allows air fromthe fan 16 to flow forwardly through the holes '34and outwardly through the space 37 between the two plates 31 and 33 tofurther aid in keeping the forward part of the spinner cooler and makethe plates more effective as radiation shields. The holes 34 may be ofvarious size and shapes but arepreferably aligned with the airpassageways 38 around the oil-slinging tube 39. The tube 39 communicateswith the hollow shaft 17 and its structure and thev structure ofassociated cooperating parts is the same as disclosed in said patent.Thus, the forward or upper end of the tube 323 is flared and provides aknife edge or lip 4% from which the oil is thrown in the form ofdroplets upon high-speed rotation of the tube. These droplets passbetween the plate 33 and the flange or plate dl of the spinner hub 42.Between these plates 33 and 41 cooperating bafiles 43 are arranged toaid in directing the droplets outwardly after they are thrown off thetube lip it) as described in my patent. i i I have found that undercertain high temperature conditions, the main transverse planar streamof fuel droplets strike the wall or pad 25 in such' heavy concentrationthat a band of carbon builds up at the surface of thewall in thetransverse plane of the travel of the heavier droplets which is in theplane of the outlet space between the spinnerplates 33 and 41. This isonly true along a narrow band intermediate the axial extent of theabsorbent wall 25. To prevent this build-up, I provide a ring 45 i ofnon-absorbent material, such as metal, in the path of the main stream ofheavy droplets thrown off by the spinner. 'However, this ring must be ofa limited extent in an axial'direction so that the satellite dropletswill contact directly with the absorbent wall 25.

Studies of this burner have shown that the spinner throws off the oil asa concentration of droplets in the transverse plane of the outlet spaceof the spinner and that this center stream contains a relatively largepercentage of the total volume of the discharged oil but that it isrestricted to aaquite narrow band, The same studies have also shown thatin diverging transverse planes to either side of the main transverseplanar stream of oil droplets, there are quite a number of lessconcentrated oil droplets which -I call satellite droplets. Theprinciple I use and which has proven very beneficial in actualoperation, is to use a non-absorbent ring or band 45 which is fairlynarrow in the axial direction radially between the spin-' ner and thewall 25 so as to intercept thetdroplets in the main stream ,of droplets,to break them up and then to direct them onto the absorbent wall 25. Thering may be located and supported in various ways'such as by the band isdisposed radially closer to the wall 25 than to the periphery of thespinner to provide a sufficient radial path for the oil droplets beforethey strike the non-absorbent band 4-5. I prefer to have the band 45closer to the Wall 25 than to the spinner and have found that thedistance between the band 45 and the wall 25 should be about to /4 theradius from the center of'the spinner to the surface of the absorbentwall 25. Then when the heavy droplets strike the ring &5, they will bebroken up into smaller droplets and be directed axially forwardly andrearwardly onto the surface of the porous wall 25 which extends axiallyforwardly and rearwardly to a substantial extent relative to the ringband 45.

Thus, it will be apparent from the diagrammatic illustrations in FIGURES5 and 6 that by using a band 45 of the type indicated and located asindicated, the main stream of droplets thrown off by the spinner in thetransverse plane of the lip 40 is broken up and dispersed and directedonto the absorbent wall, while at the same time the satellite dropletswhich are in streams in forwardly and rearwardly diverging planes onaxiallyopposite sides of the main stream travel, directly onto the wall25 and will spread axially, as well as circumferentially, in bothdirections in the absorbent wallf Similarly, when the droplets bounceoff the band 45, they contact the absorbent wall forwardly andrearwardly thereof and spread axially in both directions, as well ascircumferentially, in the wall 25. Thus, formation of carbon on theabsorbent wall by the concentrated droplets is prevented but at the 7same time, the lighter droplets are allowed to contact directly with theabsorbent Wall to provide for smooth quick starting or lighting of theburner as well as more efiicient sustained burning without carbonformation. Tests have 'such surface to the bottom of the burner and theburner could not be lighted inthe horizontal position which it does soeasily when the droplets strike the absorbent wall.

25. Any suitable lighting means may be employed. For example, anignition spark device46' may be provided in the burner directly adjacentthe exposed surface of the wall 25.

The non-absorbent surface which interrupts the travel of the main streamof droplets may take various forms in addition to that of the continuousbandor ring 45 shown in FIGURES Z, 5 and 6 and described above.

'For example, as shown in FIGURE 7, the band or ring instead ofproviding a continuous surface may be formed as indicated at 45a inFIGURE 7 where it is provided with angular-1y spaced openings or spaces5t} that permit a certain portion of the droplets of the main stream tocontact directly with the wall 25. In FIGURE 8. a similar arrangement isshown except thattadjace'nt the openings 5 012, the material from theopenings formed in the ring 451) is upturned about 45 and extends intthedirection of rotation of the spinner so as to provide baffle tabs whicheffectively engage the droplets from the spinner which are thrown off atapproximately 45 from with its angle facing toward the spinner. ln eachcase,

' a strictly radial direction.

V In FIGURE 9, I show the ring Q50 in theform'ofa heavy Wire whereas inFIGURE 10 the'ring 45d is formed of several wires arranged in atriangular cross section.

a non-absorbent surface is provided as a baffle for preventing all ofthe droplets from striking directly on the wall 25. Other bafflearrangements may be'provided.

spinner and resulting excessive carbon formation thereon. Also,according to this invention, means is provided for preventing at leastaportion of the droplets thrown off by the spinner from contactingdirectly with the absorbent wall but for permitting a certain portionthereof to contact that wall. With this arrangement, excessive carbonformation on the absorbent wall isprevented but quick and easy lightingand sustained burning is insured.

Having thus described my invention, what I claim is:

1. A liquid fuel burner comprising a combustion chamher having aperipheral wall, a spinner rotatably mounted on its axis within thecombustion chamber in radially spaced relationship to the surroundingperipheral wall of the combustion chamber and in a transverse planerelative thereto, means for supplying liquid fuel to the spinner, meansa supplying air for combustion to the spinner in cooperativerelationship with the liquid fuel supplied thereto, means for rotatingthe spinner so as to throw off the liquid fuel supplied thereto in theform of droplets in a main transverse planar stream, a liquid fuelabsorbent wall surrounding said-spinner and spaced radially outwardlytherefrom between the spinner and the peripheral wall of the combustionchamber, said absorbent wall being of material of high capillarity forreceiving droplets, of the liquid fuel thrown off by the spinner andspreading it throughout the area thereof to provide a large areaforrapid evaporation and burning of the fuel, said absorbent wallextending axiallyin both directions relative to the transverse plane ofthe spinner and the main transverse plane of the stream of dropletscreated thereby, and a battle means of nonabsorbent material located insaid main transverse plane radially between said spinner and saidabsorbent wall so that part of the droplets thrown off by said spinnerwill first contact said baflle means and be broken up and then bedirected onto said absorbent wall, said nonabsorbent bafiie meansextending axially only a portion of the axial extent of said absorbentwall to expose said absorbent wall to direct contact of some of thedroplets thrown off by the spinner, said nonabsorbent baflle meansextending axially A to the axial extent of theabsorbent wall and theradial spacing of the nonabsorbent baffie means from the absorbent Wallbeing about to A the radius from the axis of the spinner to the surfaceof the absorbent wall.

2. A liquid fuel burner according to claim 1 in which .the nonabsorbentbattle means is in the form of an annular band of flat cross-section ina direction parallel to the supplied thereto, means for rotating thespinner so as tothrow off the liquid fuel supplied thereto in the formof droplets in a main transverse planar stream, a liquid fuel absorbentwall surrounding said spinner and spaced radially outwardly therefrombetween the spinner and the peripheral wall of the combustion chamber,said absorbent wall being of material of high capillarity for receivingdroplets of the liquid fuel thrown off by the spinner and spreading itthroughout the area thereof to provide a large area for rapidevaporation and burning of 1 the fuel, said absorbent wall extendingaxially in both directions relative to the transverse plane of thespinner and the main transverse plane of the stream of droplets materiallocatedinsaid transverse plane radially between said spinner and saidabsorbent walllso that partof the droplets thrown off by said spinnerwill first contact said baffle means and be broken up and then bedirected onto said absorbentwall, said nonabsorbent bafile meansextending axially only-a portion. of the axial extent of saidabsorbentwall to expose said. absorbent wallto direct contact of some ofthe droplets thrown off by the spinner, said nonabsorbent bafiie meansbeing provided with angularly spaced, substantially radial openingsthrough which some of the droplets will pass from the spinner directlyonto said absorbent wall, and baffle tabs extending angularly inwardlyover said openings in the direction of rotationof the spinner.

4. A liquid fuel burner comprising a combustion cham- V her having, aperipheral wall, a spinner rotatably mounted spinner, means forsupplyingair for combustion to the spinner in cooperative relationship withtheliquid fuel supplied thereto, means for rotating the spinner so as tothrow off the liquid fuel supplied thereto in the form of droplets in amain transverse planar stream, a liquid fuel absorbent wall surroundingsaid spinner and spaced radially outwardly therefrom between the spinnerand f the peripheral wall of the combustion chamber, said absorbent wallbeing of material of high capillarity for receiving droplets of theliquid fuel thrown off by the spinner and spreading it throughout thearea thereof to provide a large area for rapid evaporation and burningof the fuel, said absorbent wall extending axially in both directionsrelative to the transverse plane of the spinner and the main transverseplane of the stream of droplets created thereby, and a baflle means ofnonabsorbent ma terial located in said transverse plane radially betweensaid spinner and said absorbent wall ,so that part of the dropletsthrown off by said spinner will first contact said baffle means and bebroken up and then be directed onto said absorbent Wall, saidnonabsorbent bafile means extending axially only a portion of the axialextent of said absorbent wall to expose said absorbent wall to directcontact of some of the droplets thrown off by the spinner, said spinnerbeing provided with an outer wall covered with insulation, said wallbeing spaced axially from an inner wall to provide a space whichreceives some of the air supplied for combustion, said inner wall beingprober having a peripheral wall, a spinner rotatably mounted within thecombustion chamber in radially spaced relationship to the surroundingperipheral wall of the combustion chamber and in a transverse planerelative thereto,

means for supplying liquid fuel to the spinner, means for supplying airfor combustion to the spinner in cooperative relationship with theliquid fuel supplied thereto, means for rotating the spinner so as tothrow oif the liquid fuel supplied thereto in the form of droplets in atransverse planar stream, a liquid fuel absorbent wall surrounding saidspinner and spaced radially outwardly therefrom between the spinner andthe peripheral Wall of the combustion chamber, said absorbent wallbeingof materialof-high capillarity for receiving droplets of the liquid fuelthrown olf by the spinner and spreading it throughout the area thereofto provide a large area for rapid evaporation and burning of the fuel,said absorbent wall extending axially in both directions relative to thetransverse plane of the spinner and the main transverse plane of thestream of droplets created thereby, said spinner comprising an innermostwall and an intermediate wall spaced axially outwardly therefrom toprovide a fuel space for receiving the liquid fuel to permit it to bethrown outwardly in the form of droplets upon rotation of the spinner,said means for supplying liquid fuel to the spinner comprising a passagemeans around the spinner axis leading into said fuel space, said meansfor supplying air for combustion comprising a passage means surroundingsaid liquid fuel passage means leading into said fuel space, and meansfor providing for a reduced temperature at said fuel space in thespinner to prevent evaporation of the oil before it leaves said space sothat the fuel will be thrown outwardly from that space in the formofdroplets which will reach said absorbent wall,

outer surface of said outermost wall, said insulating laminationpreventing direct exposure of the outermost wall to the flame producedin the combustion chamber of the burner and said insulating laminationand said air space reducing heat transmitted from the flame to the fuelspace between said intermediate and said innermost walls, and means formounting all of said walls for rotation together about the spinner axisas a unit.

References Cited by the Examiner UNITED STATES PATENTS JAMES W.WESTHAVER, Primary Examiner.

MEYER PERLIN, Examiner.

1. A LIQUID FUEL BURNER COMPRISING A COMBUSTION CHAMBER HAVING APERIPHERAL WALL, A SPINNER ROTATABLY MOUNTED ON ITS AXIS WITHIN THECOMBUSTION CHAMBER IN RADIALLY SPACED RELATIONSHIP TO THE SURROUNDINGPERIPHERAL WALL OF THE COMBUSTION CHAMBER AND IN A TRANSVERSE PLANERELATIVE THERETO, MEANS FOR SUPPLYING LIQUID FUEL TO THE SPINNER, MEANSFOR SUPPLYING AIR FOR COMBUSTION TO THE SPINNER IN COOPERATIVERELATIONSHIP WITH THE LIQUID FUEL SUPPLIED THERETO, MEANS FOR ROTATINGTHE SPINNER SO AS TO THROW OFF THE LIQUID FUEL SUPPLIED THERETO IN THEFORM OF DROPLETS IN A MAIN TRANSVERSE PLANAR STREAM, A LIQUID FUELABSORBENT WALL SURROUNDING SAID SPINNER AND SPACED RADIALLY OUTWARDLYTHEREFROM BETWEEN THE SPINNER AND THE PERIPHERAL WALL OF THE COMBUSTIONCHAMBER, SAID ABSORBENT WALL BEING OF MATERIAL OF HIGH CAPILLARITY FORRECEIVING DROPLETS OF THE LIQUID FUEL THROWN OFF BY THE SPINNER ANDSPREADING IT THROUGHOUT THE AREA THEREOF TO PROVIDE A LARGE AREA FORRAPID EVAPORATION AND BURNING OF THE FUEL, SAID ABSORBENT WALL EXTENDINGAXIALLY IN BOTH DIRECTIONS RELATIVE TO THE TRANSVERSE PLANE OF THESPINNER